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III-V Nanowire-based Infrared Photodetectors : Design, Fabrication and Characterization

Jain, Vishal LU (2016)
Abstract
Semiconductors are the backbone of almost every electrical or optical component, one of them being photodetectors. Photodetectors are used in many applications such as digital cameras or solar panels. They can also be designed to detect the omnipresent infrared radiation, discovered in 1800, which is invisible to human eye. Such infrared photodetectors are commercially used in e.g. night-vision, optical communication, environmental monitoring and surveillance.
With the advent of nanotechnology, the component size is shrinking rapidly, thus generating a need for new materials compatible with industrial standards. Nanowires possess all the ideal characteristics such as enhanced resonant absorption, tunable spectral response and possible... (More)
Semiconductors are the backbone of almost every electrical or optical component, one of them being photodetectors. Photodetectors are used in many applications such as digital cameras or solar panels. They can also be designed to detect the omnipresent infrared radiation, discovered in 1800, which is invisible to human eye. Such infrared photodetectors are commercially used in e.g. night-vision, optical communication, environmental monitoring and surveillance.
With the advent of nanotechnology, the component size is shrinking rapidly, thus generating a need for new materials compatible with industrial standards. Nanowires possess all the ideal characteristics such as enhanced resonant absorption, tunable spectral response and possible heterogenous integration. This thesis reports on fundamental studies of different types of nanowire-based infrared photodetectors, ultimately designed for industrial applications.
The first two studies focused on the influence of doping profile and segment lengths on the performance of p+-i-n+ InP nanowire array photodetectors. An increase in p+-segment length was found to significantly enhance the photocurrent by shifting the depletion region from the substrate far up into the nanowires. Moreover, it was shown that a low doping at the tip of the nanowires made it possible to tune the detector window with an applied bias.
A key advantage of nanowires is the possibility to fabricate quantum heterostructures. Broad near-infrared detection was demonstrated in a subsequent study by incorporating multiple InAsP quantum discs in InP n+-i-n+ nanowire array detectors.
In low-light conditions, or in applications requiring large bandwidth, an enhanced photocurrent signal is desirable. The last study of the thesis reports on the realization of a spatially separated InAsP absorption region, optimized at 1.55µm for optical communication applications, combined with an InP multiplication region, all integrated in a single nanowire.
Summarized, this thesis demonstrates the great promise held by nanowires for future photodetectors.
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Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Professor Diana L. Huffaker, Cardiff University, United Kingdom
organization
publishing date
type
Thesis
publication status
published
subject
keywords
nanowire, infrared, photodetector, APD, thermal imaging, telecommunication, fabrication, InP, InAsP, Fysicumarkivet A:2016:Jain
pages
156 pages
publisher
Lund University (Media-Tryck)
defense location
Lecture hall Rydbergsalen, Department of Physics, Sölvegatan 14, Lund University, Faculty of Engineering
defense date
2016-11-18 13:15
ISBN
978-91-7753-038-1
language
English
LU publication?
yes
id
e16fcc80-e928-49e9-94c9-18d8fd6576fd
date added to LUP
2016-10-25 12:15:07
date last changed
2017-01-25 14:18:12
@phdthesis{e16fcc80-e928-49e9-94c9-18d8fd6576fd,
  abstract     = {Semiconductors are the backbone of almost every electrical or optical component, one of them being photodetectors. Photodetectors are used in many applications such as digital cameras or solar panels. They can also be designed to detect the omnipresent infrared radiation, discovered in 1800, which is invisible to human eye. Such infrared photodetectors are commercially used in e.g. night-vision, optical communication, environmental monitoring and surveillance. <br/>With the advent of nanotechnology, the component size is shrinking rapidly, thus generating a need for new materials compatible with industrial standards. Nanowires possess all the ideal characteristics such as enhanced resonant absorption, tunable spectral response and possible heterogenous integration. This thesis reports on fundamental studies of different types of nanowire-based infrared photodetectors, ultimately designed for industrial applications. <br/>The first two studies focused on the influence of doping profile and segment lengths on the performance of p<sup>+</sup>-i-n<sup>+</sup> InP nanowire array photodetectors.  An increase in p<sup>+</sup>-segment length was found to significantly enhance the photocurrent by shifting the depletion region from the substrate far up into the nanowires. Moreover, it was shown that a low doping at the tip of the nanowires made it possible to tune the detector window with an applied bias. <br/>A key advantage of nanowires is the possibility to fabricate quantum heterostructures. Broad near-infrared detection was demonstrated in a subsequent study by incorporating multiple InAsP quantum discs in InP n<sup>+</sup>-i-n<sup>+</sup> nanowire array detectors. <br/>In low-light conditions, or in applications requiring large bandwidth, an enhanced photocurrent signal is desirable. The last study of the thesis reports on the realization of a spatially separated InAsP absorption region, optimized at 1.55µm for optical communication applications, combined with an InP multiplication region, all integrated in a single nanowire.<br/>Summarized, this thesis demonstrates the great promise held by nanowires for future photodetectors.<br/>},
  author       = {Jain, Vishal},
  isbn         = {978-91-7753-038-1},
  keyword      = {nanowire, infrared,photodetector,APD,thermal imaging, telecommunication,fabrication,InP, InAsP,Fysicumarkivet A:2016:Jain},
  language     = {eng},
  month        = {10},
  pages        = {156},
  publisher    = {Lund University (Media-Tryck)},
  school       = {Lund University},
  title        = {III-V Nanowire-based Infrared Photodetectors : Design, Fabrication and Characterization},
  year         = {2016},
}